The present invention relates to a circuit arrangement for signal processing for an inductive sensor.
It is known to utilize inductive sensors for many different measuring value determinations, in particular in connection with recognition of the position of movable parts or for a rotation rate determination, for example for determining wheel speed in lock braking systems (ABS) or for determining the rotation rate of the crankshaft and camshaft of an internal combustion engine.
Since the output signals of the inductive sensors depend substantially from the speed of the moving parts as well as from the distance between the parts to be sensed and the sensor, it is necessary to process the output signals in a specific way. German document DE-OS 32 08 262 discloses for example the approach that the output signals of an inductive sensor are processed by means of a circuit arrangement which contains in addition to other parts also a current reflector, so that the reliable further processing is possible. In the known circuit the signal amplification is not however the core of the signal processing, but instead the so-called inherent adjustment is reduced by adjusting of threshold values to the signal height. Since the signal is however not amplified, with low speeds of the parts to be tested problems can occur since the signal to be evaluated is too small.